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e85 should be higher thn that ive seen 300 on pump. we dont have e85 here so cant tell you the kind of power id expect somewhere in the 350-360 range.. but for that id just buy a used vf39 save $400 and call it a day

MAPerformance, or whatever it is, made just about 400 on a dynojet with an hta and e85. I think that was at either 26 or 28 psi. JSarv made just over 400 on an airboy plot with a regular 18g and e85 right before his car got totaled. I believe that was a 28-29 psi run with front mount, and he had previously been making 360-370ish on an sti tmic and (I think) 26ish psi. That was with an 8cm exhaust housing, which made more hp over the 7cm throughout his entire rpm range.

Really, the stock ej205 heads/cams aren't designed to make a lot of top end. Pretty much any setup is going to taper a bit up top, unless you're running such a big turbo that it's not fully spooling until almost redline.

MAPerformance, or whatever it is, made just about 400 on a dynojet with an hta and e85. I think that was at either 26 or 28 psi. JSarv made just over 400 on an airboy plot with a regular 18g and e85 right before his car got totaled. I believe that was a 28-29 psi run with front mount, and he had previously been making 360-370ish on an sti tmic and (I think) 26ish psi. That was with an 8cm exhaust housing, which made more hp over the 7cm throughout his entire rpm range.

Really, the stock ej205 heads/cams aren't designed to make a lot of top end. Pretty much any setup is going to taper a bit up top, unless you're running such a big turbo that it's not fully spooling until almost redline.

Take MAPerformance's numbers with a grain of salt. He was running on 800cc injectors and the stock intercooler at 28psi. Somehow, that math doesn't compute for me. Until that's backed up by another company, I think it's simply the dyno.

I think that 68hta would be ideal with a 8cm td06 option, it would be out powering 20g's all day. Until that happens, it's kind of a missmash of parts that work ok. There was one thread on here with a guy who gained 30whp by switching to a 10cm2 hotside on his, of course he was running a 2.1 stroker to 8k with headwork (still dropped massive power by 8k though).

I believe the the compressor housing on the 68HTA is a td05 16g housing....which makes it smaller than the 18gxtr housing.

So it seems that FP is claiming more flow throw a smaller housing......

Based on what i think the compressor housing is on a 68HTA i would give the edge to the 18gxtr all day long. Especially if you went compared 7cm vs 7cm up to 10cm vs 10cm combinations...the 18g should win, imo.

The problem is that we now have 7cm, 8cm and 10cm turbine housing available for each of these turbos.....so its a cluster phawk of different turbos all simply labeled as "68HTA" and "18gxtr". there is 6 different combinations of each turbo.

i mean a 7cm 68HTA will get killed on the topend by a 10cm 18gxtr and a 10cm68HTA might make more topend than a 7cm 18gxtr.

Basically, the turbos are so freaking close that my decision would be based on the 16g housing....its tiny.

If you wanna put things on a level playing field then it should be 47 lb/min 20gxtr vs 68HTA.....

IMO if you're looking for topend.....get a gt30 range turbo....dom1,2, or 2.5

if you get a 8cm dom2.5 the lag isnt gonna be horribly different but the topend will be wayyyyyy better.

its a fair comparison in the sense that FP is pimping the 68HTA as a 47 lb/min turbo!

FP is basically saying....look our 16g turbo will outflow any 18g and 20g you got.

How is it not fair in that sense? FP themselves is claiming that it flows the same as a 20gxtr.

I know its not fair size wise, which is why i said the td06 will flow more......but it is fair it you base the comparison on FP's flow claims.

A 47 lb/min turbo should be able to make 470whp on a Dynojet.....and none of them have even come close.

At best the 68hta makes the power of a 38-40lb/min turbo....

Quote:

Originally Posted by FP

Everyone has seen or heard about Evo3 16g turbos and TD05H 18g turbos for the Subaru 2.0 and 2.5 engines, our newest turbo is the FP 68HTA™Turbocharger for the Subaru STi/WRX unit which out flows both the E316g and 18g wheels and allows for higher PR operation without increased compressor outlet temperatures like the existing 16g and 18g wheels. Mass flow is increased to a whopping 47lb/min which is several lb/min greater than either the E316g or the 18g wheels are capable of. Rapid spool and large torque numbers are guaranteed by the TD05H turbine section.

Why don't you get the best of both worlds and do a twin scroll setup? Here's a graph from a car that I've been working on--bone stock ej205, straight pump gas, and normal bolt-on mods....well, besides the turbo from an Evo 9 and the equal length header

Holds power up top really well due to the turbine a/r, but still spools decent due to the equal length TS. Car is brutal through the first 4 gears.

The way I've always been lead to understand the lb/min-hp thing is that 47 lb/min would be 470 crank hp... No? Or are you making a stab at Dynojet numbers here??

That's the way I understood it too, 10 crank hp for ever 1lb/min flow. Garrett even mentions that in their literature.

"What is my mass flow rate? As a very general rule, turbocharged gasoline engines will generate 9.5-10.5 horsepower (as measured at the flywheel) for each lb/min of airflow. So, an engine with a target peak horsepower of 400 Hp will require 36-44 lb/min of airflow to achieve that target. This is just a rough first approximation to help narrow the turbo selection options."

I believe the the compressor housing on the 68HTA is a td05 16g housing....which makes it smaller than the 18gxtr housing.

So it seems that FP is claiming more flow throw a smaller housing......

Based on what i think the compressor housing is on a 68HTA i would give the edge to the 18gxtr all day long. Especially if you went compared 7cm vs 7cm up to 10cm vs 10cm combinations...the 18g should win, imo.

The problem is that we now have 7cm, 8cm and 10cm turbine housing available for each of these turbos.....so its a cluster phawk of different turbos all simply labeled as "68HTA" and "18gxtr". there is 6 different combinations of each turbo.

i mean a 7cm 68HTA will get killed on the topend by a 10cm 18gxtr and a 10cm68HTA might make more topend than a 7cm 18gxtr.

Basically, the turbos are so freaking close that my decision would be based on the 16g housing....its tiny.

If you wanna put things on a level playing field then it should be 47 lb/min 20gxtr vs 68HTA.....

IMO if you're looking for topend.....get a gt30 range turbo....dom1,2, or 2.5

if you get a 8cm dom2.5 the lag isnt gonna be horribly different but the topend will be wayyyyyy better.

Of course a larger turbo will generate more top end, but my question was comparing two similar turbos.

After listening to what my tuner recommended (Mike from Innovative) I went with an 18G because a 20G or larger would be too much for a 2.0 litre ej205. Sure, I'd love to drop in anything from Dom 1 to a gt35, but on a 2.0? What kind of drivability will I have in the city as a dd?

According to what's available on the market today, I'd consider the FP HTA68 or Blouch 18G-XT the top two choices, no?

My question is...which one will provide more hp with similar specs (ie. 8cm, etc)

Here's a direct comparison of a Blouch 8cm^2 18g vs. a 10cm^2 hotside hta68. The cars are tuned virtually identically by Dom. The only possibly significant difference is the 18g has a full 3" turboback, while the hta68 car has a stock STi catback.

Why don't you get the best of both worlds and do a twin scroll setup? Here's a graph from a car that I've been working on--bone stock ej205, straight pump gas, and normal bolt-on mods....well, besides the turbo from an Evo 9 and the equal length header

Holds power up top really well due to the turbine a/r, but still spools decent due to the equal length TS. Car is brutal through the first 4 gears.